The general guidance is to use gender-neutral terms in the workplace. This avoids discriminating against non-binary people, and means you don't have to ascertain everybody's gender beforehand. Suggested gender-neutral terms are "folks" or "people".
The British armed forces, specifically the Joint Equality Diversity and Inclusion unit at the Defence Academy in Shrivenham, Oxfordshire, recommend "people, folks, friends or you all", rather than "chaps" or "guys". (Source: Can a woman be a chap?, Patricia T. O’Conner and Stewart Kellerman, Grammarphobia, 15 May 2019)
Increasingly there is criticism of using potentially gendered terms such as "guys"; you can argue if they are gendered, but there is still the risk of excluding women or upsetting people. There is some support for "people" instead of "guys" (Why this woman says people should never use 'guys' to address men and women, The Independent, 1 Aug 2018). An article in The Guardian in 2016 (You don't like being called 'guys'? Come on, people!, Gary Nunn, 10 Jun 2016) rejected "people" as having less of a sense of friendly, cool collegial solidarity, but (after noting that some women are OK with "guys") suggested "folks".
This would also apply in other formal settings, such as educational institutions. If it's more casual, then you can do what you like as long as nobody objects: ladies, girls, chapesses, blokettes, ladettes.